Subcutaneous emphysema: diagnostic clue in the emergency room

Abstract

The objective of this study was to illustrate the wide spectrum of subcutaneous emphysema in the emergency room; to show the key findings on computed tomography, plain radiographs, and echography; and to discuss the differential diagnoses. Subcutaneous emphysema is a common finding in emergency department imaging studies. It has a great importance due to its broad casualty, some of them totally benign, but others potentially lethal. We retrospectively reviewed our database of emergency pathology, analyzing its origins and associated features. SE was associated to traumatic, iatrogenic, or infectious causes (necrotizing fasciitis, Fournier gangrene). It also was found associated with thoracic (causing pneumothorax and pneumomediastinum) and abdominal pathology related to intraperitoneal and retroperitoneal gas. Diagnostic difficulties and differential diagnoses are emphasized. Radiologists must be aware of abnormal gas in soft tissue because it may be the main or unique sign leading to an underlying pathology, which can be lethal.

Thoracic abnormal air collections in patients in the intensive care unit: radiograph findings correlated with CT

“…Subcutaneous emphysema occurs when air accumulates at the level of subcutaneous fatty tissue and superficially to the deep fascia that covers the skeletal muscle planes (Fig. 1) [5]. The most common clinical symptom of subcutaneous emphysema is swelling around the neck accompanied by pain in the chest [35].…”

“…are its common causes. Infectious diseases can also cause it [5]. Abnormal air comes from outside or inside of the body (pneumothorax, pneumomediastinum, PIE, retroperitoneal gas, etc.)…”

“…or from gas-forming microbes (necrotizing fasciitis, Fournier gangrene, etc.) [5,35]. Subcutaneous emphysema often causes minimal symptoms, is not critical, and does not require a specific treatment [35].…”

“…When air involves deeper tissue muscles, a characteristic radiographic finding is observed as linear lucencies with a linear disposition that follow the direction of the fascial planes and/or muscle fibers (Fig. 5) [5]. Multiple lucencies in the soft tissue can mimic alveolar infiltration.…”

“…Despite its diagnostic limitations [2,3], chest radiographs often reveal critical abnormalities that may remain unnoticed clinically. One of the life-threatening events in the ICU is the development of abnormal air collection in the thorax caused by interstitial or cystic lung disease, infectious diseases, trauma, positive pressure ventilation, and other complications associated with medical interventions [4][5][6][7][8][9][10][11].…”